package www.ym.com.controller;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import www.ym.com.common.R;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@RestController
@RequestMapping("/common")
public class CommonCtroller {

    @Value("${yangyang.path}")
    private String basePath;

    /**
     * 文件下载
     * @param file
     * @return
     */
    @PostMapping("upload")
    public R<String> upload(MultipartFile file){ //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
        //获取原始文件名
        String originalFilename = file.getOriginalFilename();
        //截取上传文件后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
        String filename = UUID.randomUUID().toString()+suffix;

//        basePath="D:\\java\\picture\\";
        //创建一个目录对象
        File dir = new File(basePath);
        if(!dir.exists()){
            //目录不存在则创建
            dir.mkdirs();
        }

        try {
            file.transferTo(new File(basePath+filename));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(filename,null);
    }
//
    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("download")
    public void download(String name, HttpServletResponse response){
        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream=new FileInputStream(new File(basePath+ name));
            //输出流，通过输出流将文件写会游览器，在游览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len=0;
            byte[] bytes = new byte[1024];
            while ((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭流
            fileInputStream.close();
            outputStream.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
